Bethesda and id Software have revealed the PC system requirements for the closed beta phase of DOOM, check it out after the break.

Minimum Spec (720p)
Windows 7, Windows 8.1, Windows 10 (64-bit versions only)
Intel Core i5-2400 or better / AMD FX-8320 or better
8 GB RAM
NVIDIA GeForce GTX 670 (2GB) or better / AMD Radeon HD 7870 (2GB) or better
Up to 22GB HDD space
Steam account
Broadband internet connection
*Please note that the NVIDIA GeForce GTX 750 Ti, and mobile GPUs are not supported for the DOOM Beta. Please check back later for minimum or recommended system specs for the final game

Recommended Spec (1080p)
Windows 7, Windows 8.1, Windows 10 (64-bit versions only)
Intel Core i7-3770 or better / AMD FX-8350 or better
8GB RAM
NVIDIA GeForce GTX 970 (4GB) or better / AMD Radeon R9 290 (4GB) or better
Up to 22GB HDD space
Steam account
Broadband internet connection

And these were the PC requirements for DOOM's alpha build:

Minimum Spec (720p)
64-bit Windows 7/Windows 8.1
Intel Core i5 @ 3.3 GHz or better / AMD FX-8350 @ 4.0 GHz or better
8 GB RAM
NVIDIA GeForce GTX 660 (2GB VRAM) / AMD Radeon HD 7870 (2GB VRAM)
6GB HDD space
Steam account
High speed internet connection

Recommended Spec (1080p)
64-bit Windows 7/Windows 8.1
Intel Core i7 @ 3.4GHz or better / AMD FX-8350 @ 4.0GHz or better
8GB RAM
NVIDIA GeForce GTX 780 (3GB or more VRAM) / AMD Radeon R9 280 (3GB or more VRAM)
6GB HDD space
Steam account
High speed internet connection